The present invention relates to compounds for use in optical fiber cables, and, more particularly, relates to compounds used as waterblocking or inhibiting agents in such cables.
A frequent requirement of optical fiber cables is impermeability to water or also longitudinal impermeability to water of the same. To achieve longitudinal impermeability to water, waterproofing agents are added to the optical fiber cables.
To ensure impermeability to water, state-of-the-art optical fiber cables are known, which have a gel-like filling compound as a waterproofing agent. This gel-like filling compound is inserted-into the optical fiber cable between the jacket of the optical fiber cable and the optical fibers enclosed by the jacket. In order to have access to the individual optical fibers during subsequent installation of the optical fiber cable, the jacket and the gel-like filling compound have to be removed. The removal of the gel-like filling compound and the cleaning of the optical fibers of the gel-like filling compound is very time consuming.
Additionally, so-called xe2x80x9cdryxe2x80x9d state-of-the-art optical fiber cables are known from. For such xe2x80x9cdryxe2x80x9d optical fiber cables, water impermeability is achieved by swell fleece as waterproofing agent, which replaces the gel-like filling compounds. Such swell fleece is formed as ribbons or yarns coated with so-called SAPs (Super Absorbent Polymers). Also known are xe2x80x9cdryxe2x80x9d optical fiber cables, where water impermeability is achieved by means of swell powder, where the swell powder is formed as SAP (Super Absorbent Polymer) and embedded into a thermoplastic support materialxe2x80x94so-called melt glues or hot melts. The mixture of thermoplastic support material and swell powder has to be processed under influence of temperature during the extrusion of the optical fiber cable jacket.
Optical fiber cable with at least one optical fiber, with a jacket enclosing each and every optical fiber, and a waterproofing agent, wherein the waterproofing agent comprises a duroplastic support material and a swell powder embedded into the duroplastic support material. In one of many embodiments of the present invention, the waterproofing agent can be characterized as a hydrophilic epoxy resin.
In a method of processing, the swellable, hydrophilic epoxy resin mixture is mixed with the second component of the duroplastic support material, namely the hardener. Here the mixing ratio coordinated with the epoxy equivalent is in the range of 0.9 to 1.1, preferably 1:1.